Renix wont start when warm

So we have a 87 renix that when it get warm and you shut it off it wont start but if we give it a shot of starting fluid then it runs fine .This is very intermitend and seem to be fuel related because tps cps ecm have all been replaced over the past year and nothing has gotten better .Ive read through loads of renix issue posts and nothing is quite the same as this .

Thanks...

Check your fuel pressure with a gauge. 31 at idle with the vac hose connected to the fuel pressure regulator and 39 when unplugged.

Picked a fuel pressure gauge up at Harbor Freight, about $30. Get the one for fuel
injection systems.

Cool I have a trip heading that way on Friday.But how would getting warm make the pressure drop or stop all together ?I guess this is why I love my H.O sop much never had any issues with the motor.

Thank you guys hope this will help

How long do you have to let the vehicle sit before it will start on its own??

The fact that you can start the engine with a shot of starting fluid verifies that you have a fuel delivery problem. Getting actual fuel pressure data as advised is not a bad idea.....But you MUST do it when symptomatic, or otherwise the test data may not be of value. But I suspect it will tell you that you don't have good fuel pressure when the engine doesn't start.

If this only happens with a hot engine, you are suffering from some sort of "thermal" (heat related) failure. You could start by swapping in a new fuel pump relay. Fuel pumps themselves don't usually suffer from thermal failure because they are not in the engine bay. So it's possible you have a fuel delivery problem that is based in an electrical fuel control problem.

birchlakeXJ said:

The fact that you can start the engine with a shot of starting fluid verifies that you have a fuel delivery problem.

Click to expand...

Lots of good advise, but

One other possibility other than fuel is a bad MAT (also called an IAT), or even a bad CTS. I had a no start in my 87, when cold problem and random high idles that vexed me for months. Would always start warm or hot, but if it was below 60 F would never start. It was a bad MAT(IAT) sensor, air temp sensor in the intake manifold. The CTS (coolant temp sensor) and MAT can be tested with an ohm meter and compared to the OEM specs table.

If the temp sensor is way off, it may be telling the ECU to starve the engine for fuel, so the Air/fuel ratio is too far off to ignite.

Great thanks going to tear into it this weekend .Also sometimes it takes 5 min last night it wouldnt start 2 hours later.

I cant seem to find any place that carries Fuel pump relay whats it look like ?

The relay is a standard "bosch" type cube. Also check out the automatic shutdown relay. That will cause the IAC to park the mixture adjust at the wrong setting and cause hard or no start.

ASD is called a B+ relay in the renix FSM.

There a bunch of these relays under the hood and dash all over the older jeeps:

http://www.delcity.net/store/Relay-!-no-mounting-bracket/p_73577.a_1

http://www.wiringproducts.com/contents/en-us/p3982.html

http://www.wiringproducts.com/contents/en-us/d36_-automotive-relay.html

http://www.wiringproducts.com/contents/en-us/p4068.html

Cool stuff Thank you and My Old man thanks you too this is for his renix